French patent No. 1,391,493 discloses polyfluorooxetanes of the formula ##STR1## where R.sub.1 and R.sub.2 is hydrogen, chlorine or fluorine. The utility of said compounds is as chemical intermediates, solvents and plasticizers characterized by a high degree of thermal stability and inertness. The polyfluorooxetanes are prepared by the photochemical reaction between fluoroketones and fluoroolefins.
J. F. Harris, D. D. Coffman, J. Am. Chem. Soc., 84, 1553 (1962) and E. W. Cook, B. F. Landrum, J. Heterocycl. Chem., 2, 327 (1965) disclose similar processes and tabulate a large number of polyfluorooxetanes prepared by this route. Such processes proceed only under UV irradiation, which significantly limits productivity and makes it difficult to use them for preparation of the compounds on a commercial scale.
U.S. Pat. No. 3,164,610 discloses the preparation of partially fluorinated oxetanes by the non-catalyzed reaction of fluorinated ketones with non-fluorinated vinyl ethers. Only highly reactive non-fluorinated vinyl ethers may be involved in the reaction.
G. G. Belen'kii, G. I. Savicheva, E. P. Lur'e, L. S. German, Bull. Acad. of Science USSR. Chem. Div., 1248 (1978) disclose the reaction of trifluorotrichloro-acetone with tetrafluoroethylene in the presence of antimony pentafluoride to give a 45% yield of a mixture comprising an open chain ketone, 1,1,4,4,5,5,5-hepta-fluoro-1,3,3-trichloro-2-pentanone (36%) and an oxetane, 2-difluorochloromethyl-2-dichlorofluoromethyltetra-fluorooxetane (64%). Also disclosed is the reaction of the same substituted acetone with trifluoroethylene in the presence of antimony pentafluoride to give a 27% yield of a three component mixture comprising an open chain ketone (22%) and two different oxetanes (67% and 11%, respectively).
U.S. Pat. No. 2,992,884 discloses the formation of oxetane containing mixtures.
V. Weinmayr, J. Org. Chem. 28, 492(1963) discloses the reaction of tetrafluoroethylene with bis (fluoro-methyl) ether (formed in situ from formaldehyde and HF) to give fluoromethyl-2,2,3,3,3-pentafluoropropyl ether and/or 2,2,3, 3, 3-pentafluoro-1-propanol depending on temperature in addition to 4 small quantity by-products one of which is 2,2,3,3-tetrafluorooxetane.